# Relationship history for MSHA mine 1901081

Current hierarchy: **Anthony A  Will → AA Will Sand and Gravel Corp → Portable Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Anthony A  Will et al → Portable Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Read Sand & Gravel → Portable Plant; 2000-04-01 to 2002-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Anthony  Nickinello → Portable Plant; 2000-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Anthony  Nickinello → Read Sand & Gravel; 2000-04-01 to 2002-03-31; source msha-controller-operator-history
- **operator_operates_mine:** AA Will Sand and Gravel Corp → Portable Plant; 2002-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Anthony A  Will et al → AA Will Sand and Gravel Corp; 2002-04-01 to current/open; source msha-controller-operator-history